CODEWITHSUNDEEP
javascript
Sydney Loteria
Sydney Loteria

Reputation: 10471

Limit items in a .map loop

I would like to ask how can I limit my .map loop for example to a 5 items only because currently when I access an api it returns 20 items. but I want to display only 5. Mostly that I found is just looping all throughout the array of objects and not limiting it to a number of items.

Note: I have no control on the API because I'm just using the moviedb api

Here's my code:

var film = this.props.data.map((item) => {
  return <FilmItem key={item.id} film={item} />
});

return film;

Upvotes: 119

Views: 164077

Answers (5)

Ali Murtaza
Ali Murtaza

Reputation: 550

here is the way you can limit items using map function.

const result = array.map((value, index) => {
        // * need only 10 items
        if (index >= 10) {
            return;
        }

        return <div key={index}>Text</div>;
    });

Upvotes: 0

Seid Akhmed Agitaev
Seid Akhmed Agitaev

Reputation: 192

You can also limit it by passing a second argument to a map() callback, which would be an index of an item in the loop.

const film = this.props.data?.map(
  (item, index) => 
    index < 5 && ( // <= only 5 items
      <FilmItem 
        key={item.id} 
        film={item} 
      />
    )
);

return film;

However, you probably should stick to Nina's answer unless you really need some elegancy in your code. Since I'm guessing my answer would be slower performance-wise.

References:

  1. MDN: map() syntax
  2. Optional Chaining

Upvotes: 10

Nina Scholz
Nina Scholz

Reputation: 386736

You could use Array#slice and take only the elements you need.

var film = this.props.data.slice(0, 5).map((item) => {
        return <FilmItem key={item.id} film={item} />
    });

return film;

If you do not need the original array anymore, you could mutate the array by setting the length to 5 and iterate them.

Upvotes: 323

ANOOP NAYAK
ANOOP NAYAK

Reputation: 551

Hi, If you are using a functional component. you can try this:

<p>const [film, setFilm] = useState([])</p>

<i>// Fetch data from API</i>

<p>useEffect(() =>{...})</p>

var fiveFilm = film.slice(0,5)

in your return function:

you can map using:

{fiveFilm.map(item => <p>{item.name}<p>)}

Upvotes: 0

hozefam
hozefam

Reputation: 1040

You could use filter() as well

var film = this.props.data.filter((item, idx) => idx < 5).map(item => {
   return <FilmItem key={item.id} film={item} />
});

return film;

Upvotes: 20

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